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101.
The effects of annealing of B or N dual implanted regions in 15-20 Μm thick monocrystalline Β-SiC films has been investigated
using cross-sectional TEM, SIMS, Raman spectroscopy, C-V and sheet resistance measurements. Implantation resulted in buried
amorphous regions (in the B films) or highly disordered regions (in the N films) and residually strained regions. Annealing
for 300 s at selected temperatures between 1173 and 2073 K caused structural reordering, precipitation (in the B samples)
and dopant diffusion, as the temperature was progressively increased. Only slight changes were noted in the sheet resistance
of either type of sample as a result of annealing to 1973 K. However, the values of this parameter decreased markedly atT > 1973 K in both implanted and as-grown samples. Thus, this phenomenon was most probably caused by the formation of additionaln-type defects in the bulk of the materials.
Presented at the 1985 Electronic Materials Conference, Boulder, CO, June, 1985. 相似文献
102.
Mullenbach GT; Chiu CY; Gyenes A; Blaney J; Rosenberg S; Marlowe CK; Brown S; Stratton-Thomas J; Montelione GT; George-Nascimento C; Stauber G 《Protein engineering, design & selection : PEDS》1998,11(6):473-480
Six mutants of human epidermal growth factor (EGF), which carry single
point substitutions within a surface patch proposed to juxtapose the bound
receptor, were prepared and characterized for receptor affinity and
mitogenicity. Receptor affinities relative to EGF are G12Q > H16D >
Y13W > Q43A approximately = H16A approximately = EGF >> L15A.
Notably, the reduced receptor affinity of mutant L15A indicates that Leu15
probably contributes substantially to receptor binding whereas unaltered
receptor affinities observed for analogs H16A and Q43A indicate that
neither His16 nor Gln43 contributes significantly to this interaction. On
the other hand, the observed enhanced receptor affinities of analogs G12Q,
Y13W and H16D highlight surface loci where additional productive
receptor-binding contacts can be introduced. Interestingly, at acidic pH
analog H16A reveals substantially greater receptor affinity than that of
EGF, a property which may offer enhanced therapeutic utility in acidic
environments in vivo.
相似文献
103.
104.
Periportal lesions were detected on ultrasound in two cases of Langerhans cell histiocytosis with liver involvement. Hypoechoic or hyperechoic lesions were detected in different stages of evolution. Hyperechoic lesions probably corresponded to periportal inflammation whilst hyperechogenicity suggested xanthomatous change. 相似文献
105.
106.
Experimental studies of RNA evolution in vitro are reviewed in the context of Eigen's 1971 theory and its subsequent extensions. Current research activity and future prospects for using automated molecular biology techniques for in vitro evolution experiments are surveyed. 相似文献
107.
108.
Glass Container Association Ring Section Sub-Committee of the Standard Testing Procedure Committees 《Journal of the American Ceramic Society》1944,27(3):85-89
The ring-section technique has been studied by the Standard Testing Procedure Committee of the Glass Container Association, and a tentative Standard Method of Examining and Grading Glass Container Ring Sections is proposed. The scope, method, and frequency of sampling, method of examination, and the methods used for ware-quality grading and glass-quality grading are described. 相似文献
109.
Conversational interfaces: advances and challenges 总被引:1,自引:0,他引:1
Zue V.W. Glass J.R. 《Proceedings of the IEEE. Institute of Electrical and Electronics Engineers》2000,88(8):1166-1180
The past decade has witnessed the emergence of a new breed of human-computer interfaces that combines several human language technologies to enable humans to converse with computers using spoken dialogue for information access, creation and processing. In this paper, we introduce the nature of these conversational interfaces and describe the underlying human language technologies on which they are based. After summarizing some of the recent progress in this area around the world, we discuss development issues faced by researchers creating these kinds of systems and present some of the ongoing and unmet research challenges in this field 相似文献
110.
Formation of small coating droplets is a phenomenon common to spray and roll application of coatings. Generation of small droplets, referred to as atomization, is the mechanism of controlling the quality and thickness of the applied coating layer in spray technology. In roll coating application, small coating droplets are formed at the nip–exit region under certain conditions. Because of the high-shear rates at roll nips and spray nozzles, it is common to relate high-shear viscosity with atomization and roll misting behavior of coatings. This paper will review the relative importance of shear and extensional flows, and the response of coatings to such flows, in affecting misting and atomization behavior. Experimental efforts to quantify the effect of shear and extensional rheological parameters have clearly established a lack of correlation of high-shear viscosities with both spray atomization and roll misting behavior of coatings. However, extensional viscosity is shown to have a strong correlation. Finally, how rheology modifiers can be selected to circumvent misting problems in roll coating applications and atomization problems in spray applications is discussed. 相似文献